Designed primarily for tracking, TL Audio's M3 tube mixer works well in a number of applications, but it excels as a front end to DAWs and other digital recorders. If you are a serious recordist looking to add tube warmth and color to your digital tracks, then your search may be over. Following in the footsteps of the acclaimed VTC tube console, the M3 TubeTracker delivers much of its larger sibling's sonic mojo in a smaller, less-expensive package.

This 8×2 mic/line mixer employs a hybrid tube/solid-state topology with balanced internal buses. The fan-cooled outboard PSU occupies two rackspaces and connects to the mixer via a 10-foot cable, providing 200 volts to its five 12AX7/ECC83 tubes — one for every two mic pre's and one in the stereo mix bus. (Because the 12AX7 is a dual-triode tube that contains two independent tube stages, it can be used in 2-channel preamps simultaneously.) The 28.6-pound M3 occupies 10 rackspaces, but comes with a wood-laminated particleboard surround for tabletop use.

In keeping with the “tracking” part of its name, the M3 has direct channel outs (post-fader, +4/-10 switchable) but no dedicated tape-return inputs. Balanced ¼-inch line inputs can be used as tape returns, but feed the same gain-control section as the mic pre's — selected via a mic/line switch — and are affected by the phase-reverse switch in the shared signal path. Each channel's gain pot has a +16 to +60dB range with a center detente for 0dB line; a drive LED indicates when the tube is overdriven.

Each channel's 4-band EQ has ±15 dB of boost/cut, fixed high- (12kHz) and low- (80Hz) shelving filters, and two sweepable mid-bands covering 500 to 18kHz and 50 to 2kHz (both with 0.7 Q). Also standard are a 90Hz HP filter, hardwired EQ bypass, two aux sends (one with pre-/post-fade switch), pan pot, mute and PFL switches, and 100mm fader. The EQ, mute and PFL switches have accompanying LEDs, and there's a peak LED on each channel.

All connections are on the rear (except headphones), with XLR mic and ¼-inch TRS line inputs on each channel, along with TRS inserts and ¼-inch (post-fader) direct outs that are +4 and -10dB switchable. The two aux sends, two stereo aux returns and stereo 2-track return are balanced ¼-inch connectors, all with +4/-10 switches — a nice touch. The main stereo outs are XLR, while the stereo-monitor outs are balanced TRS. Calibration trim pots are provided for each channel and the master outs. To use multiple M3s, two 15-pin D-sub connectors link the PFL, aux and stereo buses, with the M3 at the end of the chain serving as the master-output source.

We also tested the optional DO-1 digital-output card, which offers simultaneous output in AES/EBU (XLR) and S/PDIF (co-ax and optical) formats, as well as an internal/external sync switch and wordclock input. Switches in the mixer's master section can select word length (16/20/24-bit) and sampling rate (44.1/48/88.2/96kHz). I used the DO-1's AES/EBU output to route stereo signals to my Yamaha 03D digital mixer and its coaxial S/PDIF output to record stereo tracks in Digital Performer via a MOTU 2408 MkII interface. The DO-1's converters sounded really good in both cases — much better than the 03D's onboard converters. Unfortunately, the optical output can't carry all eight M3 channels — it's strictly a 2-channel output.

The M3's frequency response is given as 20 to 40kHz, and I had no difficulty believing it. The mixer boasts extremely open and crystalline highs, focused yet smooth mids, and a tight, solid bottom end. But there's more to it than that: There is a certain magic to the sound that no doubt has something to do with the tubes and the ultraclean signal path but, at the same time, transcends technical specs. Just running audio through the M3 — even with the gain at unity and equalizers bypassed — imbues it with this quality. That's why the M3 is an ideal front end to digital recording systems: After using it with Digital Performer for two months, I was spoiled. Plus, while recording bass, synth/sampled sounds and electric guitars, pushing it into gentle distortion created similar sounds to a tape-compression effect.

The EQs are super-sweet and beautifully voiced. The shelving filters add sparkle and roundness without brittleness or boom, and the swept mids retained their smoothness over their entire (and considerable) range. Time after time, the EQs imparted just what was needed and nothing more.

In case it isn't obvious, I love this mixer. Retailing at $3,549, it isn't cheap, but if you think of it as buying eight really nice discrete tube mic pre's, along with eight great analog equalizers — and remember that the direct channel outs allow you to configure it as eight separate outboard EQs — it's a pretty attractive package. Don't forget that those eight mic pre/EQ units can be mixed to stereo via a balanced tube mix bus (with optional digital outs), but that's just the gravy!